The Coalition for Epidemic Preparedness Innovations (CEPI) has announced the urgent fast-tracking of three investigational vaccine candidates aimed at combating the virulent Bundibugyo ebolavirus (BDBV) epidemic currently afflicting regions within the Democratic Republic of the Congo (DRC) and Uganda. This critical initiative underscores a concerted global effort to address a public health crisis for which no licensed vaccines currently exist, nor any in active clinical development prior to this announcement. Following a comprehensive global review and extensive consultations with leading health authorities, including the World Health Organization (WHO) and the Africa Centres for Disease Control and Prevention (Africa CDC), CEPI has strategically selected candidates from IAVI, Moderna, and the University of Oxford to accelerate their development.
The Urgent Threat of Bundibugyo Ebolavirus
Ebola Virus Disease (EVD) represents one of the most severe and lethal viral hemorrhagic fevers, characterized by high mortality rates and the capacity to trigger devastating outbreaks. While the Zaire ebolavirus strain is perhaps the most widely recognized, having been responsible for numerous large-scale epidemics, including the devastating West Africa outbreak of 2014-2016 and subsequent major outbreaks in the DRC, the Bundibugyo ebolavirus (BDBV) presents its own distinct set of challenges. BDBV was first identified in 2007 during an outbreak in the Bundibugyo District of Uganda, from which it derives its name. Prior to the current situation in the DRC and Uganda, there had only been two documented outbreaks caused by this specific strain, making research and development into specific countermeasures significantly less advanced than for Zaire ebolavirus.
The current BDBV epidemic in the DRC and Uganda highlights the urgent need for targeted interventions. These regions, often grappling with fragile healthcare infrastructures, internal displacement, and conflict, are particularly vulnerable to the rapid spread of highly contagious pathogens. The absence of a licensed vaccine or even candidates in clinical trials for BDBV has left communities exposed and frontline healthcare workers facing immense risks. The incubation period for Ebola can range from 2 to 21 days, and symptoms typically include fever, fatigue, muscle pain, headache, and sore throat, followed by vomiting, diarrhea, rash, symptoms of impaired kidney and liver function, and in some cases, internal and external bleeding. Without specific treatments or preventive measures, containing such outbreaks relies heavily on rapid identification, isolation, contact tracing, and supportive care, all of which are challenging in resource-limited settings.
Richard Hatchett, CEO of CEPI, articulated the gravity of the situation in a recent press release, stating, "With Bundibugyo virus spreading rapidly and no licensed vaccines, every day counts in the race against this deadly disease. CEPI’s urgent funding and support for these three promising candidates aims to advance safe, effective vaccines to help control this epidemic." This statement underscores the critical role of organizations like CEPI in addressing market failures where commercial incentives alone are insufficient to drive the development of vaccines for rare or localized diseases, despite their devastating potential.
CEPI’s Strategic Response and Global Collaboration
CEPI was founded in 2017 in Davos, Switzerland, as a partnership between public, private, philanthropic, and civil society organizations. Its primary mission is to accelerate the development of vaccines against emerging infectious diseases and enable equitable access to these vaccines for affected populations during outbreaks. Born from the lessons learned during the 2014-2016 West African Ebola crisis, CEPI recognized the critical gap in preparedness for novel and neglected pathogens. Its funding model relies on contributions from governments, foundations, and private donors, channeling these resources into vaccine research and development programs that might otherwise be overlooked.
The selection process for the three fast-tracked candidates involved a rigorous global review, assessing scientific merit, technological feasibility, scalability, and potential for rapid deployment. This evaluation was conducted in close collaboration with global public health bodies, including the WHO, which provides crucial guidance on public health priorities and ethical considerations for vaccine development during outbreaks, and the Africa CDC, which brings invaluable regional expertise and understanding of the specific epidemiological and logistical challenges in African contexts. This multi-stakeholder approach ensures that the chosen candidates are not only scientifically sound but also align with the urgent needs and practical realities on the ground.
A Trio of Promising Candidates: Diverse Technologies for a Common Foe
The three selected vaccine candidates represent distinct technological platforms, each bringing unique advantages to the fight against BDBV. This diversification strategy is crucial in vaccine development, as it increases the likelihood of success and provides flexibility in deployment, manufacturing, and potential future adaptations.
1. IAVI’s rVSV Vaccine: A Proven Platform with Significant Potential
IAVI’s candidate utilizes a recombinant vesicular stomatitis virus (rVSV) platform, a technology originally developed at The University of Texas Medical Branch. This platform works by engineering the VSV to express a protein from the target virus (in this case, BDBV), prompting the immune system to generate a protective response. A significant advantage of the rVSV platform is its capacity to elicit strong protective immunity often after a single dose, which is critical in outbreak scenarios where rapid protection is paramount.
Crucially, this is the same technological backbone used for the only licensed vaccine against the Zaire ebolavirus, rVSV-ZEBOV (Ervebo), developed by Merck. The Zaire ebolavirus vaccine has demonstrated remarkable efficacy and was successfully deployed in a ring vaccination strategy during recent Zaire ebolavirus outbreaks in the DRC, proving the platform’s utility in real-world epidemic control. Furthermore, a variant of this technology was deployed during a 2025 Sudan virus outbreak in Uganda, showcasing its versatility against different filovirus strains.
While the IAVI BDBV candidate has demonstrated protective efficacy in non-human primate studies, it has not yet undergone evaluation in humans. Despite this, the WHO has identified it as the most promising among the candidates selected by CEPI, likely due to the proven track record of the rVSV platform against related ebolaviruses. CEPI’s initial investment of $3.2 million will be instrumental in supporting the critical early stages of development, specifically funding the generation of a Master Virus Seed stock and the vital transfer of processes to a contract development and manufacturing organization (CDMO) for Good Manufacturing Practice (GMP) production. This step is essential for ensuring that future vaccine doses can be produced consistently and to the quality standards required for human clinical trials and eventual licensure.
2. Moderna’s mRNA Innovation: Building on COVID-19 Success
Moderna’s candidate leverages its cutting-edge messenger RNA (mRNA) platform, the same revolutionary technology that underpinned the rapid development and deployment of its highly effective COVID-19 vaccine. The mRNA technology instructs human cells to produce a harmless piece of the virus’s spike protein, triggering an immune response. Its key advantages include speed of development, flexibility in targeting different pathogens, and relative ease of manufacturing once the platform is established.
CEPI is making a substantial investment of up to $50 million in Moderna’s BDBV mRNA candidate. This significant funding is earmarked for preclinical testing, Phase 1 clinical trials, and crucially, simultaneous manufacturing activities. This parallel approach is a hallmark of accelerated development strategies during epidemics, designed to minimize the time lag between successful clinical data and the availability of doses. If Phase 1 trials prove successful, this funding will enable the program to advance immediately into Phase 2 and Phase 3 trials, dramatically compressing the typical vaccine development timeline.
Stephane Bancel, CEO of Moderna, reiterated the company’s commitment in the press release: "We will move with urgency and scientific rigor to support the response and help bring a potential vaccine closer to the communities that need it most." For Moderna, this collaboration with CEPI is strategically important, extending beyond immediate humanitarian concerns. The company’s financial performance in the recent past has shown a notable shift from its pandemic-era peaks. Its revenue in the fourth quarter of last year (2025) was down 30% year-over-year. The first quarter of 2026 brought in a modest $0.4 billion, with approximately 80% derived from international markets, indicating a tapering of domestic demand for its flagship COVID-19 product. In 2025, Moderna reported spending $3.1 billion on research and development expenses, while its total revenue for the year was only $1.9 billion.
In this context, CEPI’s substantial investment offloads a significant portion of the financial risk associated with a commercially challenging program. Developing a vaccine for a rare ebolavirus strain like Bundibugyo, with localized outbreaks, offers limited immediate commercial return. This grant allows Moderna to continue to validate and expand the application of its mRNA technology to new pathogens within its filovirus pipeline, accumulating critical clinical data and manufacturing experience at little financial cost to the company. This public-private partnership exemplifies how CEPI’s funding can de-risk essential vaccine development for diseases that do not attract sufficient private investment alone.
Interestingly, this substantial CEPI investment in mRNA technology contrasts sharply with policy shifts observed in the United States. In August 2025, the Trump administration reportedly terminated 22 contracts focused on developing mRNA vaccines and initiated a winding down of additional federal investments in mRNA technology. This divergence highlights differing strategic priorities and risk appetites between global health initiatives like CEPI and certain national governments regarding the future of advanced vaccine platforms.
3. The University of Oxford’s ChAdOx1 Vector: Versatility Against Filoviruses
The University of Oxford’s vaccine candidate is built upon the ChAdOx1 viral vector platform. This technology utilizes a modified chimpanzee adenovirus that cannot replicate in humans but can deliver genetic material from the target pathogen to trigger an immune response. This platform gained widespread recognition and trust through its application in the AstraZeneca COVID-19 vaccine, which was deployed globally during the pandemic.
The ChAdOx1 platform has already demonstrated promising efficacy against various related filoviruses, including Zaire ebolavirus, Sudan virus, and Marburg virus. This established cross-protective potential makes it a robust candidate for BDBV, leveraging prior research and development efforts. CEPI has committed $8.6 million to support Oxford’s candidate. This funding will cover crucial preclinical testing, the creation of a Master Virus Seed stock—similar to IAVI’s candidate—and the essential production of clinical-grade doses necessary for human trials. The proven adaptability and safety profile of the ChAdOx1 platform offer a valuable alternative in the race to develop an effective BDBV vaccine.
Navigating the Development Pathway: Fast-Tracking and Future Steps
The "fast-tracking" of these vaccine candidates signifies an expedited development pathway, which compresses timelines by running certain stages in parallel and prioritizing regulatory review. Typically, vaccine development can take a decade or more, but in an epidemic context, this timeframe is drastically reduced through coordinated efforts and emergency protocols. This includes early engagement with regulatory authorities to streamline approval processes, rapid mobilization of manufacturing capabilities, and efficient clinical trial designs.
As work on these three leading candidates commences, CEPI remains committed to a comprehensive and adaptive strategy. The organization will continue to evaluate additional promising candidates, including through an ongoing open call for proposals. This ensures that no viable solution is overlooked and that the global scientific community’s full potential is harnessed.
Beyond development, CEPI is actively coordinating with key global health and financial institutions to ensure future success translates into widespread access. Collaborations with Gavi, the Vaccine Alliance, which focuses on equitable access to vaccines for low-income countries; the World Bank, a vital source of development financing; and other development finance institutions are critical. This coordination aims to ensure that surge financing mechanisms are in place for large-scale procurement and distribution should any of these trials prove successful. The goal is not just to develop a vaccine, but to ensure it reaches the populations most in need, thereby preventing future outbreaks and saving lives.
Broader Implications and the Future of Vaccine Development
The fast-tracking of these BDBV vaccine candidates carries significant implications extending beyond the immediate crisis. Firstly, it underscores the vital role of public-private partnerships, exemplified by CEPI, in addressing global health inequities and market failures. Without CEPI’s intervention, the development of a BDBV vaccine, a product with limited commercial appeal, would likely languish.
Secondly, the deployment of diverse vaccine platforms – rVSV, mRNA, and ChAdOx1 – in response to a single outbreak showcases the growing maturity and versatility of modern vaccinology. Each platform offers unique strengths, from the proven efficacy and rapid single-dose protection of rVSV, to the unprecedented speed and adaptability of mRNA, and the established safety and broad applicability of viral vectors. This diversification enhances global health security by providing multiple tools to combat emerging threats, accelerating the learning curve for future pandemic preparedness.
The substantial investment in Moderna’s mRNA platform, particularly against the backdrop of reduced government funding for mRNA research in some Western nations, highlights a potential divergence in strategic priorities. While some political entities may be retracting support, global health organizations like CEPI recognize the transformative potential of mRNA technology, not just for COVID-19 but for a wide array of future pathogens, including rare and neglected diseases. This strategic investment by CEPI could help sustain and further validate mRNA technology development, ensuring its continued advancement for global public good.
Finally, this initiative reinforces the critical importance of a proactive approach to epidemic preparedness. Rather than reacting solely after an outbreak has escalated, CEPI’s model aims to fund vaccine development for known high-threat pathogens even when they are not actively circulating, thereby shortening response times when an outbreak does occur. The current BDBV epidemic serves as a stark reminder that while one pathogen may dominate headlines, the threat of others persists, requiring continuous vigilance, sustained investment, and robust international collaboration to safeguard global health. The collective efforts to accelerate these BDBV vaccine candidates offer a beacon of hope for communities currently battling this deadly virus and represent a crucial step forward in the ongoing fight against emerging infectious diseases.
